A gold or silversmith generally begins the process of forming wire by casting a 2-inch long cylindrical ingot of metal about 1/2-inch in diameter. The ingot is then rolled to a nearly square cross section of about 1/8-inch across the flats. This slender metal bar is then drawn through a draw plate several times each time with successively decreasing diameter holes until a wire of the desired size is obtained. During the drawing process, the wire is annealed several times and lubricated with wax before being pulled through the drawplate.
It is known in the art to have machines that make wire of gold or silver. Typically, the previous machines have been large and expensive and therefore not economically available to the small-business craftsman nor able to be stored in small quarters in which these craftsmen often work. It is therefore the more common practice for craftsmen to draw the precious metal through a draw plate by hand, requiring considerable muscular effort. To draw metal by hand, these craftsman need to purchase metal stock in sizes that allow them to pull the stock through a draw plate, foregoing the option of using scrap material.
The present invention provides a machine that is comparatively small so that it can be accommodated in a jeweler's small business area. It is designed to be simple and cost-effective to be affordable to the small business craftsman. It is motorized to facilitate operation yet retains the advantages of hand drawing. That is, it clamps to the metal being drawn through the draw plate with adjustable force on the grasping mechanism; the draw plate is securely held during drawing, but easily repositioned for subsequent draws through successively smaller hole; and, the machine is compact and so easily stored in small areas.
It is then the object of this invention to provide a machine for drawing precious metals into wire that is compact and affordable to the small-business craftsman.
It is a further object that the machine be motorized for ease of use, but retain the simplicity and advantages of drawing wire by hand.
It is still another object that the motor attachment be provided with a release mechanism so that when tension on the wire reaches a predefined limit, the motor is disengaged.
It is yet another object that the machine provide a adjustable mechanism for grasping the metal for drawing through the plate for use with metals of varying hardness and size.
It is still another object that the machine operate at gradually adjustable speed.
It is a final object that the draw plate be adjustably mounted on the machine to facilitate alignment through several successive draws of wire through the plate.